Process for dyeing of nylon fibers with premetallized and acid dyestuffs



United States Patent 5 Claims; (Cl. 8-55) ABSTRACT OF THE DISCLOSURE .The invention is stripping and redepositingdye from a dyed nylon fabric to level the dyeing-thereof by applying a solution of a nonylphenol ethylene oxide condensate having 84-86% ethylene oxide group, i.e. about 21-295 ethylene oxide groups per molecule, and Water soluble amine, amide or ammonia. The nylon in the solution is maintained at 160 F., then heated at 205 to 210 F. cooled to 190, acidified with an acid generator such as ammonium acetate or ammonium sulfate and then reheated. Short chain alkylamines, alkenylamines alkanolamines, alkanoic acid amide, piperazene, morpholene, pyrrolidene, N-methyl derivatives of pyrrolidone and morpholene, and ethylene oxide condensates of these amides with up to 3 moles of ethylene oxide per amide group are some of the amines and amides used.

.T he present application is a division of applicants pending'application, Ser. No. 204,616, filed June 22, 1962.

'The present invention relates to the art of dyeing. More particularly, this invention relates to a process for dye ing of fibers, yarns and fabrics composed of polycarbonamide superpolymers, more familiarly and hereinafter referred to as nylon, and an aqueous dyebath suitable therefor. a

.Heretofore, according to customary practices, thedyeing of a nylon was carried out by employing dispersed or acetate-dyestuffs because of their great covering power and their insensitivity to variations in constitution normally encountered in the manufacture of nylon fibers. But, however, the use of dispersed or acetate dyestuffs Was'lirnited in application because of their lack of fastness to light and washing. With the advent of the application of acid dyes, milling dyes and neutral dyeing premetallized dyes to a nylon fiber, yarn or fabric, the problem of fastness to lightand washing was alleviated but here again these dyes appeared extremely sensitive to'variations in the com-.

position 'of the nylon fiber in that the dyes did not level and did not yield well-penetrated dyeings. In addition, a further difiiculty encountered has been the necessity for complete stripping ofuneven dyeing because of the lack of available leveling agents. 1

'Thus, a primaryobjectof this invention is to provide a new and improvedaqueous dyebath suitable for dyeing nylon.

- A further object of this invention is the provision of a new and improved process for dyeing nylon.

It is still anotherobject of this inventionto provide a process for the dyeing of .nylon which will produce level, well-penetrated dyeings on said nylon.

It is a further object of thisinvention to provide a process for dyeing nylongfibers withneutral dyeing premetallized colorswhich produces dyed fibers, yarns and fabrics characterized by excellent light and fastness and wetfastness.

Still anotherobject of this invention is the provision of a new'and improved process for even and-level dyeing of "ice nylon without streaks and variations in depth of shade.

A still further object of the invention contemplates the feature of an aqueous dyebath composition suitable for stripping dyestuffs from an unevenly dyed nylon fiber, yarn or fabric and re-dyeing of the unevenly dyed nylon fiber, yarn or fabric.

These and other objects of the invention will become further apparent from the detailed description of the invention hereinafter. I

The attainment of one or moreof the above objects of the invention is accomplished by treating nylon with an aqueous dyebath containing a water-soluble, non ionic surface active agent containing apolyoxyalkylenehehain and derived from an active hydrogen-containing cornpound. U

A further embodiment of this invention is directed; to the feature of enhancing the levelling action andis,;;accomplished by the employmentof a combination of a non-ionic surface active agent containing a polyoxyalkylene chain with an activator. It has been found that the aforesaid combination is particularly useful for stripping and redyeing of unevenly dyed nylon and in the'ca'se-of neutral dyeing premetallized colors, the aflinity of nonionic surfactant-activator combination for the dyestuit' is so great that the dyestuff is removed from the nylon fiber, yarn or fabric into the aqueous dyebath so that when acidgenerating salts are added tothe dyebath, the dyestuffs in the bath are gradually released upon continued dyeing and return evenly and uniformly to the nylon fiber, yarn or fabric. l I 1 The non-ionic surface active agents which have been found unusually effective as leveling agents for premetallized and acid type dyestuffs are the nonylphenoxypolyoxyethylene glycols containing 84 to 88% combined ethylene oxide. Indeed, it is quite surprising to. find that the non-ionic surface active agents of the class described above provide optimum leveling action on nylon since experimental data indicates that such specificity ofaction is lacking in nonylphenol-ethylene oxide adducts containing or 90 percent ethylene oxide and octyl anddodecylphenol-ethylene oxide adducts containing percent combined ethylene oxide. 1

The activatorswhich can be employed to enhance the leveling action of the aforesaid non-ionic surface active agents include ammonia and relatively non-volatile organic amines and amides which are water-soluble to the extent of at least one weight percent. Preferably and in addition to the degree of desired water solubility of the organic amines and amides, they should have boiling points of at least 70 C. or greater at atmospheric pressure. It is also preferred that they should not be highly odoriferous. Rep, resentative organic amines and amides which find utility in carrying out the process of the invention include. alkyl amines, alkenyl amines, alkanolamines, aromatic and heterocyclic amines such as methylamine, ethylamine, triethylamine, di-n-propylamine, isopropylamine, diisopropylamine, butylamine, dibutylamine, amylamine, diamylamine, triamylamine, ethanol'amine, propanolamine, dimethylaminoethanol, ethylaminoetlianol, isopropylaminoethanol, dibutylaminoethanol, acetamide, caproamide, caprylamide, pyrrolidone, N-methyl pyrrolidone, piperazine, pyridine, morpholine, morpholene, N-methyl morpholone and the like.

Another class of activators which are useful in the process of the invention are amides reacted .with from one to three molar proportions of ethylene oxide suchas N- (beta-hydroxyethyl -n-butyranilide, N- (beta-hydroxyethyl) -n-caproamide, N-(beta-hydroxyethyl) caprylamide, N-(beta-hydroxyethyl)-n-caproanilide, N beta-hydroxy: ethoxyethyl-n-caproamide, N beta hydroxyethoxyethyl caprylamide and N-hydroxyethoxye thyl derivatives of caproamide, caprylamide, n-butyranilide, n-caproanilide and the like.

The amount of nonylphenoxypolyoxyethylene glycol surfactant above-described which is employed in carrying out the process of the invention is not necessarily a critical feature of the invention. Recommended amounts which can be employed to secure advantageous results can vary from 0.25 to 10.0% by weight based on the weight of fiber although amounts less than or greater than the above recommendation can be employed if desired. Similarly,'the amount of activator to be employed for stripping and redyeing of unevenly dyed nylon in combination with surfactant is not a critical feature of the invention. Advantageous results can be obtained by employing amounts of activator varying from 1.0 to 2.0 percent by weight based on the weight of fiber.

The acid-generating salts which can be readily employed with facility in carrying out the process of this invention are the ammonium salts of inorganic and organic acids. Representative ammonium salts include ammonium acetate, ammonium borate, ammonium carbonate, ammonium citrate, ammonium formate, ammonium oxalate, ammonium persulfate, ammonium sulfate, ammonium tartarate and the like.

The process of the invention is admirably suited for use with all types of nylon superpolymers and comprises the reaction products of polymerforming compositions containing amide-forming groups, for example, reaction materials comprising bi-functional molecules containing at least two reactive groups which are complementary to reactive groups in other molecules and which include the complementary amide-forming groups. These synthetic polycarbamates which comprise the self-polymerization products of monoamine monocarboxylic acids containing at least five carbon atoms in the chain separating the amino function and the carboxyl function and those synthetic linear polycarbamates derived from the reaction of suitable diamines with suitable dicarboxylic acids in substantially equimolar amounts. It is to be understood that reference herein to the amino acids, diamines, and dicarboxylic acids is intended to include the equivalent amide-forming derivatives of these reactants. Upon hydrolysis, the amino acid polycarbonamides yield the amino acid hydrochloride and the diamine-dicarboxylic acid polycarbamates yield the dicarboxylic acid and diamine hydrochloride. Further, the average number of carbon atoms separating the amide groups in the nylons is at least two.

The nylons are characterized by the recurrence in the molecule of the group NRCO wherein R is a member of the group consisting of hydrogen and monovalent hydrocarbon radicals, as a part of the main chain of atoms in the polymer. Particularly useful nylons applicable in the process of the invention are the simple unsubstituted nylons, such as those formed by the reaction of tetramethylene diamine and adipic acid, tetramethylene diamine and suberic acid, tetramethylene diamine with sebacic acid, hexamethylene diamine and adipic acid, or the polymerization products of n-epsilon-caprolactam. In addition, polymers formed from the reaction of two or more diamines with dicarboxylic acids and/or two or more dicarboxylic acids with diamines are contemplated as providing suitable nylons for practice in the instant invention.

The dyestuffs which can be advantageously employed in carrying out the process of the invention are readily available in commerce and well known and described in the literature and patented arts. In general, the acid dyestuffs suitable for :use herein are those water-soluble dyes commonly employed for dyeing wool, and contain at least one carboxylic, sulfonic, sulfone or sulfonamide group of a substituted derivative thereof and are applied from a neutral to acid aqueous medium. A great number of them are of the azo type (mono-, di-, and polyazo dyestuffs). However, other groups of acid dyes are also operaa als tive in carrying out the process of this invention and in elude, for example, the quinoline, pyrazolone, and dior triphenylmethane colors, the acid anthraquinones, the dyes derived from xanthene such as the cosines, phthaleins and sulforhodamines and the chromoxan dyes derived from oxytrimellitinic acid. The dyestuffs may be pre-metallized, such dyestuffs being generally described as metallized acid or metallized'azo dyestuffs. Such dyestuffs are available under such trademarks as Palatine Fast Colors, Neolane, Inochromes, Chromacyls, Chromolans, Vitrolans, Cycolans, Suprulans, and the like. The mordant acid dyestuffs are also operative herein, such dyestuffs being metallized on the fiber in the usual manner, subsequent to treatment in accordance with the process of the instant invention. As metallized and mordant acid dyestuffs suitable for use in the process of this invention, those. preferred contain in the 0,0 positions relative to an azo linkage, well known groups, for example hydroxyl or carboxyl groups and the like, which are capable of forming complexes with metals.

In general, the amount of dyestuff employed in the aqueous dyebath will vary depending on the results desired. Ordinarily, from about 1 to about 8 ounces of commercially available dyestuff (about 0.75 to 6.0 percent by weight) of liquor is sufficient to achieve satisfactory results.

In carrying out the process of the instant invention, a nylon fabric is immersed in a water bath containing the water-soluble, non-ionic surface active agent having a polyoxyalkylene chain as described above and circulated therein for a period of about 5 minutes. Subsequently, a dyestuff previously dissolved and diluted, is added to the water bath containing the surface active agent and the nylon fabric. The material is then run for a suitable period of time such as about 10' minutes with the temperature being raised to about 200 F. over a period of 45 minutes and dyeing continued at this temperature for a period of about an hour. At the end of the dyeing cycle, the bath is dropped and the fabric rinsed well in water at a temperature of about F.

In carrying out the process of the invention when employing an unevenly dyed piece of nylon fabric, fiber or yarn, satisfactory leveling and stripping can be obtained by introducing the unevenly dyed piece of nylon fabric into 30 to 1 liquor ratio bath at F. and adding to said bath a non-ionic surfactant of the class described and an amine and subsequently raising the temperature slowly to a temperature in the range of from 205 to 210 F. While maintaining this temperature for a period of from 1 to 2 hours. Subsequently, the bath is cooled to a temperature of F. whereupon an acid splitting salt, previously dissolved in water, is added in aliquot portions if desired, preferably over a period of about /2 hour whereupon the bath is reheated to the aforesaid higher temperature and maintained at that temperature for a period of about 1 hour. The bath is then dropped and the fabric rinsed well in water at 80 F. and dried. In this manner, the original unevenly dyed and poorly penetrated fabric will be well penetrated, evenly dyed and show the original depth of shade.

The following examples, in which parts are by weight unless otherwise indicated, will serve to illustrate the practice of the instant invention and are considered representative of the scope of the invention and are not to be regarded as a limitation thereof. In all cases, the dyeing was carried out in 30 to 1 liquor ratio bath.

EXAMPLE 1 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant, prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide, whereupon there is added 1 percent by weight based on weight of fabric,

of a previously dissolved and diluted dyestuff, prepared by diazotizing 2-aminophenol 4-dimethyl sulfonamide, coupling with 1-acetylamino-7-naphthol and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 There is obtained a well-penetrated level, dyeing which exhibits good fastness to washing, light and rubbing,

EXAMPLE 2 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by Weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuff prepared by diazotizing anthranil acid, coupling with phenyl methyl pyrazolone and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 3 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on Weight of fabric, of a previously dis solved and diluted dyestutf prepared by diazotizing 2- amidophenol 4-sulfonamide, coupling with phenyl methyl pyrazolone and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 4 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing a 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuff prepared by diazotizing 4-chloro, Z-amidophenol, coupling with phenyl methyl pyrazolone 4-dimethyl sulfonamide and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 5 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuff prepared by diazotizing 4- chloro, Z-amidophenol, coupling with 13-naphthol and metallized with cobalt. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at F. There is obtained a well-penetrated level dyeing.

EXAMPLE 6 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuif prepared by reducing and diazotizing 4-chloro-5-nitro,2-amidophenol, coupling with 1-naphthol 3-sulfonamide and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 7 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestufi prepared by diazotizing 2- amidophenol, 4-dimethyl sulfonamide, coupling with the bis diethyl sulfonamide of H acid and metallized with cobalt. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 8 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuif prepared by diazotizing 2- amidophenol 4-dimethyl sulfonamide, coupling with the his diethyl sulfonamide of H acid and metallized with chromium. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a well-penetrated level dyeing.

EXAMPLE 9 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted ldyestuff prepared by diazotizing Z-chloro, 4-amidoprhenol, coupling with phenyl methyl pyrazolone 3-sulfonamide and metallized with cobalt. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and dyeing continued at this temperature for one hour. At the end of the dyeing cycle, the bat his dropped and the fabric is rinsed well in water at 80 F. There a well-penetrated level dyeing.

EXAMPLE 10 A nylon suiting fabric is circulated for a period of five minutes in an aqueous dyebath containing 2.0 percent by weight based on weight of fabric of a nonionic surfactant prepared by condensing ethylene oxide with nonylphenol until the product contains 86 weight percent of combined ethylene oxide whereupon there is added 1 percent by weight based on weight of fabric, of a previously dissolved and diluted dyestuff prepared by diazo tizing 4-nitro, '2- amidophenol, coupling with phenyl methyl pyrazolone 3-sulfonamide and metallized with cobalt. The fabric is run for ten minutes whereupon the temperature is raised to 200 F. over a period of 45 minutes and [dyeing continued at this temperature for one hour. At the end of is obtained the dyeing cycle, the bath is dropped and the fabric is rinsed well in water at 80 F. There is obtained a wellpenetrated level dyeing.

EXAMPLE 11 factant was omitted from the dyebath, was leveled by immersing the same in a bath maintained at a temperature of 160 F., adding 5 percent by weight based on weight of fabric of previously dissolved nonylphenoxypolyoxyethylene glycol containing 86.0 percent by weight of combined ethlene oxide and 2 percent by weight based on weight of fabric of triethanolamine. The temperature of the bath is raised slowly to 205 F. to 210 F. and maintained at this temperature for 1 /2 hours. The bath is then cooled to 190 F. whereupon a solution of ammonium acetate, corresponding to 5 percent by weight based on weight of fabric, is added in three portions over a period of twenty minutes. Subsequently, the bath. is reheated to 205 F. to 210 F. for a period of one hour whereupon the bath is dropped and the fabric rinsed well in water at 80 F., extracted and dried. The original, uneven, poorly penetrated fabric is well-penetrated, evenly dyed and exhibits original depth of shade.

EXAMPLE 12 Unevenly dyed fabric prepared by the method of Example 7 without nonionic surfactant, was leveled and wellpenetrated by treating according to forth in Example 11.

EXAMPLE 13 Unevenly dyed fabric prepared by the method of Example 8 without nonionic surfactant, was leveled and well-penetrated by treating according to the procedure set forth in Example 11.

What is claimed is:

1. A process for stripping and redyeing unevenly dyed nylon material to produce a well-penetrated level dyeing which comprises introducing said material into an aqueous solution'containing a nonylp'henoxypolyoxyethylene glycol containing from 84 to 88 weight percent combined ethylene oxide and an activator selected from the group consisting of ammonia, amines and amides soluble in water to the extent of at least one percent, maintained at a temperature of about F., heating said solution to an elevated temperature in the range of from 205 F. to 210 F. for a period of time sufficient to effect stripping of said material, cooling said solution to a temperature of F; and adding an acid-generating salt to said solution and reheating said solution to said elevated temperature for a period of time suflicient to produce said wellpenetrating level dyein-g. v

2. The process of claim 1 wherein the amine is triethanolamine and the acid-generating salt is ammonium acetate.

3. The process of claim 1 wherein the amide is N- methyl pyrrolidone and the acid-generating salt is ammonium acetate.

4. The process of claim 1 wherein the amine is triethanolamine and the acid-generating salt is ammonium sulfate.

5. The process of claim 1 wherein the amide is N- methyl pyrrolidone and the acid-generating salt is ammonium sulfate.

the procedure set References Cited UNITED STATES PATENTS 2,888,313 5/1959 Mautner 8-55 3,281,201 10/ 1966 Mautner 8-5 5 NORMAN G. TORCHIN, Primary Examiner.

D. LEVY, Assistant Examiner. 

